Stiffener for hydraulic cylinders



Sept. 25, 1951 DAY 2,569,038

STIFFENER FOR HYDRAULIC CYLINDERS Original Filed Aug. 5, 1946 3 Sheets-Sheet 1 INVENTOR: /HERBERT 0. 0/; y

BY m ATTORNEY Sept. 25, 1951 H. 0. DAY 2,569,038

STIFFENER FOR HYDRAULIC CYLINDERS Original Filed Aug. 5, 1946 3 Sheets-Sheet 2 INVENTOR: HERB ER 7 0 DA Y ATTORNEY Iii 4 .1

Sept. 25, 1951 H. 0. DAY

STIFFENER FOR HYDRAULIC CYLINDERS 3 Sheets-Sheet 5 Original Filed Aug. 5, 1946 [Ill FIGS.

INVENTOR:

HfRfif/QT 0. 0A Y Patented Sept. 25, 1951 UNITED STATES PATENT OFFICE STIFFENER FOR HYDRAULIC CYLINDERS Herbert 0. Day, Bowling Green, Ohio Original application August 3, 1946; Serial No.

688,386. Divided and this application September 15, 1948, Serial No. 49,421

This invention relates to hydraulic power or hoist cylinders, hydraulic jacks, or telescoping jack devices, and more particularly to those that are swingably mounted and are thus capable of moving a swinga'ble load. Further particularized, this relates to improvements in stiffener or bracing members for the kind of power cylinder that is mounted upon and extends transversely with respect to a shaft member, to be swingable about the axis of that shaft member, while a reciprocable piston rod in the cylinder is being extended or retracted.

For example, such a power cylinder and transverse shaft member may serve in actuating the tiltable-body of dump trucks, in which case the shaft member extends across and is journalled upon the chassis frame of the truck. Hence the power-stress reactions from the cylinder upon the shaftymember, especially undesirable bending stresses; due to centrally concentrated transverse load -%-jupon the shaft member are minimized or avoided. So it is an object of this invention to solve that problem by devising means to preclude forceflreactions from the cylinder to be imposed or concentrated upon the middle portion of the shaft member by distributing or spreading the transverse reaction force or load along the length of the shaft member or to transmit it to points as close as possible to the journal-supported end portions of the shaft member. In some respects this problem and its solution is illustrated in my Patent No. 2,453,975, filed August 3, 1946, from which this patent has been divided.

Although this invention is herein shown to be embodied in the tilting mechanism of a dump truck, that embodiment is not to be considered as limiting with respect to other fields of application. For example, the improved construction may'servein swingably'raising and lowering the boom of a vehicular crane.

' According to this invention, I provide at each side of the cylinder a stifiener or rib-like loadtransmitting or -bracing member. Each bracing member is thus disposed substantially in a plane with the axes of the cylinder and of the shaft member representing a, three-cornered structure, the two base corner portions of which are fastened to respective points of the adjacent portion of the cross shaft member, while the third corner portion is fastened to the free or forward end portion of the cylinder. Adjustable means are 1 Claim. (01. 18934) provided for individually fitting or tensioning each bracing member when the same is' being mounted in place.

According to one feature, the three-cornered bracing member is in the nature of a boxstructure or rectangular triangle. Accordinglto another feature, the adjustable means comprise an eccentric device. According to still another. feature, the base edge portion of the triangular box structure or bracing member is shaped to hu the adjacent circumferential portion of the shaft member, whereby it aligns itself with the shaft member. Suitable clamping or anchoring means surround the shaft member in connecting the box structure thereto.

The swingable cylinder together with the crossshaft member represents a T-shaped structure in which the cross-shaft member is the head and the cylinder is the stem of the T. The head is supported at each end for absorbing a load acting transversely upon the head when a compressive load is imposed upon the stem of the T; This invention provides an attachment comprising a pair of box-shaped bracing members in the form of right-angled triangles symmetrically disposed with respect to the stem and with their gfplanes extending in the plane of the T so that the right angled corner portions of the members lodge in respective right angles formed by the junction of the head with the stem, with inner fastening means attaching these portions to the head. One pair of acute-angle portions of the triangles are pointing in opposite directions, each being disposed adjacent to a respective supported end of the head, with outer fastening means attaching each such portion to the head. The other pair of acute-angle portions of the triangles are codirected and disposed adjacent to the stem each being rigidly attached to the stem by means of an eccentric-containing device. The eccentric in each such device is operable or adjustable to effect pretensioning of the stem along with precompression of the bracing members for thereby diverting the compressive load from the stem to the supported ends of the head.

The best embodiment of the invention now known to me has been chosen for illustration purposes, but it should in no sense be taken as limiting because obviously the invention is capable of other embodiments with changes both in detail and construction, so long as they do not depart from the ambit of the appended claim. In the drawings:

Figure l is a perspective view of the power cylinder mounted upon the chassis of a dump truck;

Fig. 2 is an exploded plan view of the cylinder unit;

Fig. 3 is a plan view of the cylinder unit;

Fig. 4 is a perspective detail view of one of the load-transmitting bracing members;

Fig. 5 is a cross-section on line 5-5 of Fig. 4;

and

Fig. 6 is an enlarged sectional view of the adjustable mounting means for the load-transmitting bracing member. V

Environmentally, the swingable cylinder unit C is shown in Fig. 1 to be mounted by means of journals I and II, upon the chassis frame F of a dump truck, to serve in tilting the body thereof when dumping a load therefrom. The rear end of the chassis frame F has swingably mounted thereon as at 2, a tiltable body l3 fractionally.

indicated by longitudinal members l4 and I and a cross member l6 to which attaches the piston rod [1, which is extendable from, and retractable into, the cylinder I8 proper of the cylinder unit C.

Through a bore l3 (see Figs. 2 and 3) in the rear end [8 of the cylinder 18, extends a cross shaft member l9, the ends of which are rotatable in the journal [0 and H mounted upon the inside of longitudinal members 20 and 2| of the frame F rigidly interconnected as by cross members 22 and 23.

As shown in Figures 1, 2 and 3, the cylinder unit 0 comprises a pair of force-transmitting bracing members 24 and 25 of triangular shape although of box-like construction, more clearly shown in the enlarged part-sectional detail perspective of Fig. 4. The box structure is welded and comprises a top plate 26 and an identical bottom plate 2'! in the shape of a rectangular triangle, a pair of converging side walls 28 and 29, and an intermediate wall or rib 3i! converging with the side walls. The side wall 28 and the intermediate rib 33 together terminate in a tab or eye portion 3| to serve in anchoring the first or pointed or forward end or corner portion 32 of the bracing member to the front end portion of the cylinder l8.

At or near the second or right-angle corner 33 .Of the box shape there is provided a pair of bolts 34 and 35 welded respectively to the top plate 26 and the bottom plate 27. At the third or outer corner portion 36 of the box shape there is provided a half-shell hearing or rest portion 31 welded to and extending between the diverging ends of the side wall 29 and the intermediate wall or rib 30, and incidentally also welded to the top and bottom plates 26 and 21. The outer corner portions of the triangular top and bottom plates are also provided with registering bolt holes 38.

The wide rear end portion of each of the triangular box-like bracing members is fastened to the cross shaft member 19 by a half-shell clamping member 39 slipped over the bolts 34 and 35 and held tight by a pair of nuts 39 The outer corner portion of each bracing member is held in place relative to the cross shaft member l9 by means of a U-shaped steel band 60, having a fastening bolt Ml extending through the bolt holes 38 and a nut 40- The pointed or forward corner portion 32 of each bracng member is fastened to a corresponding forward end portion .of the cylinder ill, namely, to an eye portiondi welded to the Cy i der and associated with the eye portion 3| of the bracing member. Referring more specificallyto the detail in Fig. 5, the means for this fastening 4 comprise a through-bolt 42 with nut 43-, which bolt extends through an eccentric bushing 44 which is rotatably fitted into the eye portion 3| of the bracing member.

In assembling the component parts which constitute the cylinder unit C, the cross-shaft member I9 is first inserted into, and positioned in, the transverse-bore I8 of the cylinder proper. The bracing members 2 and 2,5 are then added by first positioning and fastening the wide or rear- 1 end portion thereof upon the corresponding portions of the cross shaft member I9. and then fastening the pointed or forward-corner portion 32 to the front-end portion of the cylinder. A tight fitting and unitary rigid connection or junction of the bracing members with the cylinder and with the cross shaft member can then be effected by turning the eccentric bushing 44 until tight, and then tightening the nut 43 upon the bolt 42. In this manner a solid and exceedingly strong unitary structure is created from the component parts comprising the cylinder I8, the cross shaft member l9, and the bracing members 24 and 25, through which unfavorable stresses upon the cross shaft member are effectively absorbed and transmitted to the journal l0 and II.

The rear end of the cylinder I8 has a rectangular flange portion 46 to which is bolted as at 16 a hydraulic control or master valve unit 41 having a central lever 48 to operate the powercylin der IS. A pump 49 to furnish the hydraulic pres: sure fluid is shown to be unitary with the control valve 41, being driven through a universal joint 58 by a shaft 51 from the truck engine (not shown). Suitable ports and flow passages connect the valve unit 41 with the power cylinder and with a reservoir, but are not specifically shown. The valve control lever 48 may be actuated from the drivers seat as through crank shaft 52 being linked to the control lever 48 by a rod.

When adjusting the eccentric bushing, it may be turned in one direction whereby the cylinder is placed under compression stress and the bracing member under tension stress; or the bushing may be turned in the opposite direction whereby the stress relationship is reversed, placing the cylinder under tension stress and the bracing member under compression stress. By adjusting in :the last-mentioned manner, the force reaction from the power cylinder and from the piston rod is more assuredly transmitted through the bracing members to the respective end portions of the cross shaft member.

It .will be noted in the perspective view of Fig. 1 that the parts pertaining more directly to the invention have been accentuated by heavier lines and shading, while the more environmental parts have been toned down by lighter lines or by omitting the shading.

I claim:

Anattachment in combination with a T-shaped structure having its head supported at each end for absorbing a load acting transversely upon the head when a compressive load is imposed upon the stem of the I, said attachment comprising a pair of box-shaped bracing members in the. form of right-angled triangles symmetrically disposed with respect to the stem and with their planes extending in the plane of the T so that the right.- angled corner portions of the members lodge in respective right angles formed by the junction of the head with the stem, with each of one pair of acute-angle portions of the triangles disposed adjacent to a respective supported end and the other pair of acute-an le portions of the triangles being co-directed with each of them disposed adjacent to the stem, inner fastening means attaching the right-angled portion of each bracing member to the head, outer fastening means for attaching each of said one pair of 5 acute-angle portions to the head, an eccentriccontaining device rigidly attaching each of said other pair of acute-angle portions to the stem, the eccentric in each said device being operable to effect the pre-tensioning of the stem along with pre-compression of the bracing members for thereby diverting the compressive load from the stem to the supported ends of the head.

HERBERT 0. DAY.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,090,826 Austin Aug. 24, 1937 2,210,143 Day 1- Aug. 6, 1940 2,226,213 Wood h Dec. 24, 1940 2,234,134 Barrett Mar. 4, 1941 2,453,975 Day NOV. 16, 1948 

